Double telescope.



. A. KNIG. DOUBLE TELESOOPE. *APPLIOATIOE P ILBD HAR. 19, 1908,.

918,752. Patented Apr. 2o, 1909.

fla'. is!

UNITED STATES PATENT OFFICE.

ALBERT KNIG, 0F JENA, GERMANY, ASSIGNR T0 THE FIRM 0F CARL ZISS, 0F JENA,

, GERMANY.

DOUBLE TnLnscors.

Specification of Lettera Patent.

Patented April 2o, isos.

Application led latch 19, 1908. Serial No. 422,123.

To all whom 'it may concern.:

Be it known that I, ALBERT KNIG, a citizen of the German Empire, and residing at Carl-Zeiss strasse, Jena, in theGrand Duchy ofSaxe-Weimar, Germany, have invented' a new and useful Double Telescope, of which the following is a specification.

The invention consists in an improvement in double telescopes having elevated entrance pupils, that is to say, having a difference in height between the' entrance and the exit pupils, such differencepermitting observations being made over some obstacle while the observer is under cover of it. Double telescopes of this kind have hitherto been manufactured as hinged telescopes, that is, with a hinge jointbetween the two single telescopes. As is well known, in such hinged telescopes the distance between the exit pupils is adapted tothe inter-pupilary distance of the observer by altering the angle included by the single telescopes a little. This adjustment to the inter-pupilary distance alters at the same time the distance between the entrance pupils, uponwhich distance the degree of the stereosco ic `effect is dependent, and likewise alters-t ou h in a contrary sense-the elevation of t e entrance pupils above the exit fIlililijls and thereby the measure of the use eight `of the 'cover with given height ofthe eyes'. Both .latter alterations 'are insignificant and only occur when the instrument is handed over to another observer having other inter-pupilary distance. It would be, however, advantageous, if every observer could use the instrument with large-distance between the entrance upils, where vthe cover is low, and

be -compeHed to'content himself with a small amount of this distance only, where lthe instrument has to be adapted toahigh cover.

The present invention fulfilsl the requirement just mentioned. t Its object is a double telescope, each of the two objective casings of which optical axis parallel to the section of. entrance of the respective gle telesco e, whereby both objective casings can lbe coupled to produce an equally large but opposite'motion. This motion evidently does not alterthe position of the sections of exit of the two optical axes,' consequently the l distance between the exit pupils remains unchanged. For adapting the distance between the exit lis rotatable about asection'of the mss pupils to the inter-pupilary distance any one of the known means suited to this purpose may be employed.- In general in this Vadaptation also an alteration of' the relative osition of the entrance pupils i s involved, w ich is, however, slight, and which by virtue of the rotatability of the objective casings can be again nullified.' In the special case where the means of adaptation consists in the rotation of one or both ocular casings about a section ofthe optical axis parallel to the 'section of entrance, the relative position of the entrance pupils remains unaltered. This means ermits of realizing 4a articularly simple orm of instrument. ach of the two optical axes may be so shaped, that it only'contains one 'ddle section which is parallel to the axis of entrance. This middle section then becomes the common axis of rodistance between the exit pupils to the interpupillary distance, which somewhat influences the relative positionfof the entrance upils, does'not exclude a relatively simple Form of the instrument bein realized. An arrangement, for example, or each single telescope is to be recommended, in which no middlesection whatever of the optical axis is parallelto the section of entrance. The section of exit then becomes the axis of rotation of the objective casing or the complete single telescope may be made rotatable aboutit. In the-sim lest form the o tical axis is composed of t ee sections, t creare therefore onl two reflecting prisms necessary.

IyIithe annexed drawing: Figure 1 is a back cording to the invention, the objective casings being rotated into a horizontal position.

back view of another double telescope con-v structed'accord' tothe invention, the obview of a double telescope constructed ac- 1 Fig.. 2 is a sectional side view of thesame instruinent, the objective casings being rotated'into a'vertical position. Fig. 3 is a.

j eetive casings bemg rotated into an upward position at iight angles to eachother. Fig. 4 is a sectional side view ofthe same instrument, the obective casings being rotated into a vertica csition. Fig. 5 1s a back view of a third ouble telescope constructed according to the invention, the objective casbeing rotated into an upward position at right angles to eachothen Fig. 6 is a sectional side view of the same instrumentL the rot objective casings being rotated into a vertical position.

The example in Figs. 1 and 2 discloses ay form of the invention in which either optical axis comprises only one mlddle section which is parallel to the section of entrance and.

wardly directed conical pivot c". The two objective caslngs a are coupled `by toothed sectional wheels a", whose circumference is so great, that they remain engaged, if the objective casings be turned into the direction of the ocular casings for transport purposes. In this example it is further assumed, that a sufficient hinge friction is provided for the objective casings, in order to be able to dispense wlth a de vice for checking these casings 1n any position. The ocular casmgs b are only to such an extent rotatable as corresponds to the range of inter-pupilary dis? tances. One of them may be'rigidly connected With the main casing c. The optical system of either single telescope comprises, besides the two pairs of prisms d e and f g, an objective h, a collective lens 'i placed in or near the image plane of this objective, an inverting lens system c, whose image plane may be situated in the hinder surface of the prism g, and the two lenses Z and m of a Ramsden ocular.

In the example according to Fi s. 3 and 4, the middle lenses 1', and 7c and t e pair yof prisms f g, both shown in the first example, are substituted by the image-erecting prism n, by which means the ocular casings b are shortened into bland the main casing c is modified into c1. The image plane of the objective h may coincide with the hinder face of the rism a.

T e example Figs. 5 and 6 presents greater deviations from the iirst one. Each telescope casing consists of only just the objective casing a1 and the `ocular casing o. Each objective casing is rotatable about its ocular axis and again coupled With the other to equal but opposite motions. For this purpose on the carrier p of the single telescopes, which is equipped with the pivot p0, a slotted standard p1 is arranged. Two links g are on the one side connected with the objective casings and on the other with a sliding piece r, which is guided in the slot of the standard p1 and can be secured in any place of this slot, corresponding to any position of the objective easing a, by means of a checking screw s. The adjustability of the distance between the oculars is attained by the ocular casings o being guided in the carrier p and their projections o0 being iixcd to the nuts 0, so that the set-screw t placed in the standard p1 and provided with right and leit screw threads may serve to move the oculars by equal but opposite lengths. The optical out fit of the objective casings al is the same as that of the preceding example. rl`he image lane of the objective lies, however, near the iiinder surface of the prism c. The ocular casings ocontain the lens system i 7c Z 7a, i rom the iirst example, combined to forni an image-erecting ocular. Instead of forming the ocular casings o as sliding pieces, they can be also firmly connected with the objective casings a* and placed in special sliding pieces, so that either single telescope is turned as a whole about its ocular' axis. In both cases, for adjusting the distance between the oculars, instead of the device described l'or moving the ocular casings in a straight line, such an one ior turning these casings about a common hinge axis can be chosen.

I claim:

1. A double telescope each oi' whose single telescopes is provided with an optical system, the axis of which is broken and comprises parallel sections including the entrance section, and an objective casino rotatably mounted about a section paralll to the cntrance section.

2. A double telescope each oi' whose single telescopes is provided with an optical system, the axis of which is broken and comprises a section intermediate the objective and the ocular and parallel to the entrance section,l

and an objective casing rotatably mounted about said intermediate section, at least one of the single telescopes having anocular caslng likewise rotata ly mounted about the said intermediate section.

ALBERT KONIG. VVitnesSes:

PAUL KRGER, FRITZ LANDER. 

